#
# set -o errexit is assumed.
#

TIMESTAMP_FMT="${TIMESTAMP_FMT:-"%Y/%m/%d %H:%M:%S"}";

check_prereqs() {
	for _cmd in "$@"; do
		if ! command -v ${_cmd} >/dev/null; then
			log_msg fail "Error: missing prerequisite command \`${_cmd}";
			exit 1;
		fi;
	done; unset _cmd;
};

date() {
	command date +"${TIMESTAMP_FMT}";
};

fetch() {
	wget --no-check-certificate -N ${1};
	if [ $# -eq 2 ] && ! compare_hash ${1##*/} ${2}; then
		log_msg fail "Error: hash mismatch for URL \`${1##*/}'.";
		exit 1;
	fi;
};

fetch_git() {
	if [ -d ${1} ]; then
		(cd ${1} && git pull origin main);
	else
		git clone ${2} ${1};
	fi;
};

compare_hash() {
	_hash_cmp=${2}; set -- $(openssl dgst -sha256 ${1});
	shift $((${#}-1)); set -- ${1} ${_hash_cmp}; unset _hash_cmp;
	[ "x${1}" = "x${2}" ];
};

is_build_script_done() {
	_script_fname=${SCRIPT_FNAME##*/};
	if [ -f ${WORKDIR}/.${_script_fname%.build}.${1} ]; then
		unset script_fname;
		return 0;
	else
		unset script_fname;
		return 1;
	fi;
};
set_build_script_done() {
	_script_fname=${SCRIPT_FNAME##*/};
	_done_fname=${WORKDIR}/.${_script_fname%.build};
	while [ $# -ge 1 ]; do
		if [ "x${1#-}" != "x${1}" ]; then
			rm -f ${_done_fname}.${1#-};
		else
			touch ${_done_fname}.${1};
			log_msg info "Finished build step ${1} of build script \`${_script_fname}'.";
		fi; shift;
	done;
	unset _script_fname _done_fname;
};

log_msg() {
	_lvl=${1}; shift;
	case ${_lvl} in
		fail) printf "\033[91m"; ;;
		info) printf "\033[97m"; ;;
		succ) printf "\033[92m"; ;;
	esac;
	if [ $# -gt 1 ]; then
		printf "==> %s %s %s\033[0m\n" "$(date +"${TIMESTAMP_FMT}")" "${1}" "$*";
	else
		printf "==> %s %s\033[0m\n" "$(date +"${TIMESTAMP_FMT}")" "${1}";
	fi;
	unset _lvl;
};

parse_with_pkg_name() {
	_pkg_name=${1}; shift;
	while [ $# -ge 0 ]; do
		_pkg_url=${1}; _envvs="${2}"; _pkg_fname=${_pkg_url##*/};
		if [ "x${_pkg_fname%%-*}" = "x${_pkg_name}" ]; then
			_IFS="${IFS}"; IFS=:;
			for _envv in ${_envvs}; do
				export ${_envv};
			done; IFS="${_IFS}"; unset _envvs _envv;
			_pkg_subdir=${_pkg_fname%%.tar*};
			eval _pkg_sha256sum=\${PKG_$(echo "${_pkg_name}" |\
				tr a-z A-Z)_SHA256SUM};
			return;
		fi; shift 2;
	done;
	unset _pkg_name _pkg_url _envvs _pkg_fname _envv _IFS _pkg_subdir;
};

rm_if_exists() {
	while [ $# -gt 1 ]; do [ "x${1%[a-z]}" = "x-" ] &&\
		eval _${1#-}flag=1; shift; done;
	_dir=${1};
	if [ -d ${1} ]; then
		rm -rf ${1} || return 1;
	fi;
	if [ ${_mflag:-0} -eq 1 ]; then
		unset _mflag; mkdir ${1} || return 2;
	fi;
	if [ ${_cflag:-0} -eq 1 ]; then
		unset _cflag; cd ${1} || return 3;
	fi;
};

run_configure_with_extra_args() {
	_IFS="${IFS}"; IFS=","; _script=${1}; _extra_args="${2}";
	shift 2; ${_script} "${@}" ${_extra_args}; IFS="${_IFS}";
	unset _script _extra_args;
};

set_build_dir() {
	export _build_dir=${1}-build-${2};
};

set_env_vars() {
	_val=${1}; shift;
	while [ $# -ge 1 ]; do
		export "${1}=${_val}"; shift;
	done; unset _val;
};

split() {
	_IFS="${IFS}"; IFS="${1}"; set -- ${2};
	IFS="${_IFS}"; echo "${*}"; unset _IFS;
};

# vim:filetype=sh